1. Field of the Invention
The present invention relates to the field of integrated circuits. More specifically, the present invention relates to the art of controlling input/output (I/O) of an integrated circuit, which applies equally to controlling I/O of a functional block of an integrated circuit of an embedded design type.
2. Background Information
All integrated circuits (or chips) have I/O pins to facilitate input and output of data values. Typically, the functional purposes of the I/O pins of a chip are defined, and combinatorial logic are employed to effectuate the functional behavior of the I/O pins. This prior art approach of employing combinatorial logic to control the I/O pins of a chip suffers from a number of disadvantages, including:
1. a large portion of the real estate of the chip being taken up by the I/O pin control combinatorial logic, and
2. the combinatorial logic must be redesigned for those I/O pins redefined with different functional purposes for different variants of the chip.
Thus, a more flexible or adaptable approach to controlling I/O of a chip is desired.
The above description including the disadvantages applies equally to functional blocks of integrated circuits that are of the embedded design type, where the functional blocks are inter-coupled by coupling the I/O signals of the functional blocks to on-chip buses, as if the functional blocks are physically different chips and the I/O signal lines are "I/O pins". Thus, a more flexible or adaptable approach to controlling I/O of a functional block of a chip is also desired.
As will be disclosed in more detail below, the present invention provides a more flexible and adaptable approach as desired. From the description to follow, these and other advantages will be apparent to those skilled in the art. In the description to follow, the term "I/O pin" is intended to include the emerging usage and meaning of the term, i.e. internal interface signal lines that are configured and managed as if they are external interface signal lines, as well as the historical usage and meaning of the term.